The invention relates to a connecting device for electrically connecting a three-phase motor.
Three-phase motors having at least three windings and being adapted to be connected to a three-phase network which comprises three electrical phase lines having phase-shifted alternating voltages are known. Such three-phase motors are used in a star connection or in a delta connection depending on the application. Depending on the selected connection, the ends of the windings of the three-phase motor have to be connected in different manners known per se to the phase lines of the three-phase network. The way of connecting the windings to the phase lines also determines the direction of rotation of the motor.
In the prior art, the wiring is realized manually in situ in a so-called motor connection box into which the motor winding terminals and the phase lines are guided. This wiring is very time-consuming and in case of a change of the connection or of the direction of rotation of the motor, it requires a re-plugging of the corresponding terminals, which leads frequently to errors. Tests in which plug connectors are used for the coupling are also known. Here, the motor connection box is partially dispensed with. A change of the connection and of the direction of rotation however always requires a rewiring.
Document EP 2 086 066 discloses as a post-published document a connecting device for electrically connecting a multiphase electric motor to a power source, which is made up of a connection box and a substantially cylindrical adapter.
Document DE 20 2006 016 472 U1 discloses a connector plug unit for three-phase motor units having a bridge circuit module within the connector housing. A bridge circuit is realized in the bridge circuit module, which is required for driving the three-phase motor unit by means of a delta connection.
Documents U.S. Pat. No. 3,525,971, FR 2617651 and DE 30 43 538 A1 each disclose plug connectors which can cause a reversal of the direction of rotation of a motor connected to a three-phase network by a rotated mounting or by interposing an adapter.
An object of the invention is to make the motor connection box, also known as motor terminal box, unnecessary. It is also an object of the invention to permit the electrical connection on the cable side using a connecting device by means of which both the direction of rotation of the motor and the type of the connection used can be selected in situ without a manual re-plugging/rewiring of the motor winding ends being necessary in case of a change of the connection or of the direction of rotation of the motor.